(19)
(11) EP 2 579 446 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.04.2015 Bulletin 2015/14

(43) Date of publication A2:
10.04.2013 Bulletin 2013/15

(21) Application number: 12186964.8

(22) Date of filing: 02.10.2012
(51) International Patent Classification (IPC): 
H02P 6/00(2006.01)
(84) Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME

(30) Priority: 03.10.2011 JP 2011219304

(71) Applicant: Makita Corporation
Anjo, Aichi 446-8502 (JP)

(72) Inventors:
  • Ichikawa, Yoshitaka
    Anjo, Aichi 446-8502 (JP)
  • Omura, Motohiro
    Anjo, Aichi 446-8502 (JP)
  • Yanagihara, Kenya
    Anjo, Aichi 446-8502 (JP)

(74) Representative: Kramer Barske Schmidtchen Patentanwälte PartG mbB 
European Patent Attorneys Landsberger Strasse 300
80687 München
80687 München (DE)

   


(54) Motor current detection apparatus, motor controller, and electric power tool


(57) A motor current detection apparatus in the present invention includes: a current detection unit (R0), a first filter (42, 73, 92), and a second filter (43, 74). The detection unit (R0) detects a conduction current flowing from a battery (19) to a brushless motor (30) and outputs a conduction current signal corresponding to the detected conduction current. The first filter (42, 73, 92) extracts a first current signal which is included in the conduction current signal outputted from the detection unit (R0) and is a signal component in a frequency band equal to or lower than a predetermined first cutoff frequency. The second filter (43, 74) extracts a second current signal which is included in the conduction current signal outputted from the detection unit (R0) and is a signal component in a predetermined frequency band within a frequency band equal to or lower than a predetermined second cutoff frequency higher than the first cutoff frequency and having the second cutoff frequency as a maximum value.







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